This invention relates to an improved process for electroplating a printed circuit board wherein the surfaces of the circuit board are partially covered with a masking tape comprising a foil-like carrier of paper or plastic and a coating of an adhesive material applied to one side of the carrier and being self-adhesive or adhered by means of a heat activation process.
Masking tapes of this kind are known and serve the purpose of keeping predetermined surfaces of printed circuit boards to be electroplated free from deposits. For this purpose, these surfaces are covered by the masking tape. The known masking tapes have, however, substantial disadvantages which will be explained below. If the surfaces of the printed circuit board to be electroplated have no electrical connection to the electroplating cathode, the connection of the surfaces to be electroplated with one another and with the electroplating cathode must be made by additional conducting paths, in that, for example in the case of printed circuit boards with plug connectors to be gold-plated, each plug connector is electrically connected by means of a conducting path additionally produced on the printed circuit board to a conducting path extending along the plug connectors and being likewise produced on the printed circuit board, the latter conducting path being electrically connected to the frame of the printed circuit board which is connected to the electroplating cathode. The production of the additional conducting path is, however, expensive as regards the required time and labor. In addition, the electroplating process results in a useless gold-plating of the additional conducting paths. Finally, it cannot be avoided that the copper layer provided on the printed circuit board is bare at those points at which during the separation of the frame from the printed circuit board the individual additional conducting paths are detached from the plug connectors. The copper layer will be affected at these points by influences of the environment.